1. Field of the Invention
The field of art to which this invention pertains to is the lubrication art, and more particularly to a lubricant filling device for a wheel hub.
2. Description of the Prior Art
The prior art discloses a variety of wheel hubs such as that shown in coapplicant's pending application Ser. No. 515,782, filed Oct. 17, 1974, disclosing a dual disc wheel for a highway trailer which is incorporated by reference herein.
The prior art discloses a variety of wheel hub designs having oil reservoirs within them which provide lubrication for the hub bearings which are sealed within the hub. However, because the reservoir must be sealed within the hub when it is mounted on the axle of a trailer or other vehicle, difficulty has been encountered in filling or charging the hub reservoir with oil and thereafter insuring the integrity of the seal of the reservoir within the hub. More particularly, in the past it has been necessary to monitor the hub for a substantial period of time after filling its reservoir with oil to determine if the reservoir is properly sealed within the hub. However, even when this procedure was rigidly adhered to, under static conditions oil leaks from the hub reservoir were not always detected until after the hub was put into service and the dynamics of the oil in the system and the temperature changes promoted leaks and the wheel bearings failed due to overheating and wear caused by inadequate lubrication.
The present invention presents a novel hub filling device and a facile method which momentarily detects leakage, one embodiment of the invention having a lubricant supply source and a pressurized air source connected to a common probe through which the reservoir is alternatively first charged with lubricant under high pressure and thereafter charged with air at a relatively low pressure without the necessity of disconnecting the apparatus from the hub assembly, whereby saving of time is attained and no additional equipment is required and which realistically simulates the dynamic conditions during operation of the mechanism.